Grinding apparatus



July 1, 1952 E. A. NICHOLS 2,601,747

GRINDING APPARATUS Filed March 51, 1949 6 Sheets-Sheet l 0 V o V i a I i: "W

15 L /v 0 i a W \O I i C ,Q I

. INVENTOR. EDWIN A. NICHOLS AT TOP/V5! 6 Sheets-Sheet 2 INVENTOR. EDWIN A NICHOLS ATTOPNEY.

E A NICHOLS GRINDING APPARATUS July 1, 1952 Filed March 51, 1949 y 1, 1952 E. A. NICHOLS 2,601,747

GRINDING APPARATUS Filed March 51, 1949 6 Sheets-Sheet 3 INVENTOR. EDWIN A NICHOLS iMM ATTOPNEK July 1, 1952 NICHOLS Z,6Q1,747

GRINDING APPARATUS Filed March 31, 1949 6 Sheets-Sheet 4 INVENTOR. EDWIN A. NICHOLS ATTOF/VE K July 1, 1952 E. A. NICHOLS GRINDING APPARATUS 6 Sheets-Sheet 5 Filed March 31, 1949 5 Y A 5 mm N TH P we 0 m w A M W E Y a July 1, 1952 E. A. NICHOLS 2,601,747

GRINDING APPARATUS Filed March 51, 1949 6 Sheets-Sheet 6 l8 INVENTOR.

EDWIN A. NICHOLS ATTOFNEY Patented July 1, 1952 GRINDING APPARATUS Edwin A. Nichols, Springfield, Mass, assignmto American Bosch Corporation, Springfield, Mass., a corporation of New York Application March 31, 1949, Serial No. 84,639

3 Claims.

This invention relates to grinding apparatus and has particular reference to new and improved apparatus for grinding or forming accurate leads or edges on parts of precision apparatus such as fuel injection apparatus.

An object of the invention is to provide a new and improved apparatus of the type set forth which is. particularly adapted for accurately forming parts that require a high degree of accuracy such as the plungers of fuel injection apparatus.

Another object of the invention is to provide a new and improved apparatus for forming the helix or metering edge on the plungers of fuel injection apparatus. 1 1

Another object of the invention is to provide a new and improved apparatus for forming an accurate lead on a cylindrical surface.

Another object of the invention is to provide a device of the type set forth which employs a relatively large grinding wheel.

Another object of the invention is to provide a new and improved device for forming an accurate helical lead ona cylindrical surface using as large a grinding wheel as possible for high surface speed.

Another object of the invention is to provide a device of the type set forth which is relatively simple and economical in construction yet efficient in operation.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that changes may be made in the details of construction and arrangement of parts without departing from the scope of the invention as expressed in the accompanying claims, as the preferred form has been given by way of illustration only.

Referring to the drawings:

Fig. 1 is a front view of one form of a device embodying the invention;

Fig. 2 is a top or plan view thereof; Fig. 3 is an end view thereof;

Fig. 4 is a fragmentary sectional view taken on line 4-4 of Fig. 2 looking in the direction of the arrows;

Fig. 5 is a fragmentary sectional view taken on line 5--5 of Fig. 2 looking in the direction of the I arrows;

on line 1-1 of Fig. 2 looking in the direction of the arrows;

Fig. 8 is a fragmentary sectional view taken on line 8-8 of Fig. 2 looking in the direction of the arrows;

Fig. 9 is a side view of a part for fuel injection apparatus before the forming thereon of the plunger and grinding wheel during the forming of the metering edge on the plunger; and

Fig. 12 is a fragmentary view generally similar to Fig. 11 but on an enlarged scale.

The device embodying the invention comprises broadly, a support for the work which is to have an accurate lead ground thereon; such as a plunger for fuel injection apparatus, a cutter such as a grinding wheel and means for moving said cutter and work relative to each other in such manner that an accurate lead will be formed on the work. The actuating means may be hydraulic or mechanical and in the construction shown by way of illustration consists of a hydraulically actuated work support adapted to move the work in a helical cam controlled path relative to the grinding wheel whereby an accurate helical metering lead will be formed onthe plunger.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, the device shown embodying the invention comprises a base I supporting the grinding head 2 on which is mounted the grinding wheel 3 for rotation in the usual manner. Wheel is preferably fixed relative to the work and preferably the wheel employed has an angular surface on its periphery which angle is the difference between the angular relation of the Work and the grinding wheel.

The grinder l and grinding head 2 shown are of conventional design and other conventional design grinding machines may be employed.

On the grinder l is supported the base 4 on which is mounted the carriage 5 for longitudinal movement thereon as hereinafter described and which is provided with the cam drum 6 and cam l. The cam 1 is secured to the cam drum 6 by means of bolts or the like 8 which may be removed to allow the positioning of various cams on the cam drum depending upon the part to be formed. It will be noted from the drawing that the diameter of the cam l is many times as great as the diameter of the work piece or plunger l8 on which the metering lead is to be formed. This minimizes greatly any errors in the finished lead.

The carriage 5 is provided with openings 9 adjacent its opposite ends and across 'each of which extend a pair of spaced guide bars [9, each of which extends through a sleeve or bushing I i The guide bars in are adapted to extend through bushings ll extending through projections l2 on the base 4.

The grinding.

"26. gland Z'I and packing 28.

In this manner the carriage 5 is mounted for longitudinal movement on the base 4 and the extent .ofsuch movement is controlled by the size of the openings 9 and the length of the sleeves ID as shown in Fig. 4.

The cylinder 13 is secured to the end of the carriage 5 and is adapted to receive the-piston M which is secured to the projection I2 on the base 7 4 by means of the connector l5 w'hichis "secured to said projection If. The connector l5 is'positioned between the pair of sleeves l and also is preferably positioned. substantially'in alignment therewith.

The cylinder [3 is connected by line 38 through a two-way check valve to a fluid supply and line 39 also is connected to a suitable fluid-supply whereby a uniform pressure is :maintai'ned 'in cylinder'l3 throughout the stroke'of piston M in both directions and line 38 supplies fluid to the cylinder [3 on the return stroke of carriage and maintains back pressure throughout-the forward strokeofcarriageE. It willbe seen that the position of ithe piston '14 is fixed relative to the base 4 as it is'connected thereto by connector -l5 and that the cylinder which is fixed-on car- "riage 5 reciprocates with said-carriage upon'the reciprocation thereof.

On the'carriage '5 is positioned-the adjustable supporting member '35 carrying the centering pin 16 which is resiliently urged by the spring fl for maintaining the'workpiece 18 in aligned rela- 'tion and the otherend of said workpiece I8 is secured in the chuck i9. "able on the slide 36 on carriage 5 and is adapted The support'35 is slidto be locked in adjusted position by set screws 31. 'The 'cam -1 and cam drum fi 'areadapted-to'be "rotated by the hydraulic motor 20 which is cou- *pled with the drive coupling 2| by means of the member 22 which is connected to the' rotor 23 {of the motor '20 atone endand hasits opposite "end keyed to the drive coupling 21 'by means of the woodruff key 24.

The hydraulic motor 20 is of the eccentric vane-type and includes the vane 25and springs The motor -20 is-provided with the stuff box The hydraulic motor 29 is connected to the -fluid'inlet line 41 and fluid outlet line '42, al-

"though it is reversibleby changing line 4 I to an "outlet line and line 4-2 to an inlet line.

The cam l is adjustable longitudinally to- "gether with carriage 5 to position the work in desired relation with grinding wheel 3 by means of micrometerscre-wt' i which may carry indicia which maybe read against indicator 45, and

adjustment of micrometer screw 44 adjusts the position of stop orcam follower 45 which abuts the face 40 of cam I when said cam is at the beginning of its working position. As cam i rotates against follower it, 'the carriage 5 is The drive coupling 21 is provided with the coupling cushioning blocks 29.

The cam drum 6 iskeyed to the shaft so which is journaled in the ball bearings 31 and$2 in the housing 33 which is supported on the carriage 5 and adapted to be moved longitudinally therewith.

On theiend of'theshaft 3.0:isprovided the centerine chuck IQ for retaining'theworkpiece iaiin 4 operative position in cooperation with centering pin [6.

The "device of the present inventioni'is; particularly adapted to 'form or-grind'accurate helical leads on a cylindrical surface using as large a wheel as possible for high surface speed, and is particularly adapted for the forming of accurate helical metering leads on the plungers of fuel injection apparatus as shown in the drawings.

'In forming-such plungers the blank is milled away at -to=form the helical lead or shoulder 4.8 as-shown in Fig. 10, and by using the machine of this invention the bevelled helical lead 49 is formedon the edge of the lead 48 with the lead 49 being of required accuracy.

i'InFi v9 aaside view of :a complete plunger 'blank is'ishownpriorto thefforming of the heli- "cal lead thereon'and in Fig. l0,the portion ot tween the center 16 and chuck "4'9 'and the micrometer screw M adjusted 'to properly-position theworkJB relative to the grinding'wheel 3.

The cylinder l 3 and piston then are brought into action to cause longitudinal reciprocation of the carrier 5 and work I8 relative to said grinding wheel 3 and simultaneously with the reciprocation of said carrier T5, the hydraulic motor'2il is causedto rotate and'beingconnected to the work support, therefore, causes Isimnltaneofi's-rotationofthe work l8 thereby causing the work 18 and grinding "wheel to engage .over

the desired portion of the helical lead- 48 whereby the accurately formed bevelled lead screw 49 will be formed-0n the "edge of the lead '48.

From the foregoing it will-be seen thatirhave provided means for obtaining all of the objects and advantages ofthe invention. 7

Having describedmy invention, -I claim:

1. In a-device of the character described, :a grinding wheel, a reciprocating work supporting carriage having a pair of spaced work supports adapted to support a -work'piece*relative to said grinding wheel and to be movable -axially iand rotatably, acam follower and "a rotatable face cam engaging said "followeron said support "and substantially axially aligned with said work supports and adapted to move said work support and work piece relative to'said cutter, hydraulic means for reciprocatingsaid carriage and hydraulic means forioperating'said cam.

2. In a device of the character described, a grinding wheel, a reciprocating work supporting carriage having a pair of spaced work supports adapted-to support-a Work piece relative to said grinding wheel and to be movable axially and rotatably, a'cam follower and a rotatable "face camengaging said follower on said supportand substantially axially aligned with said work supports and adapted to move said work support and work piece relative to said grinding wheel and hydraulic means for operating said cam and reciprocating said carriage, said grinding wheel being supported in angular relation "with the work piece with the difference between the angularirelation of the 'work piece andface ofthe 5 grinding wheel being the angle formed on the periphery of the grinding wheel.

3. In a device of the character described, a cutter, a reciprocating work supporting carriage having a pair of spaced work supports adapted to movably support a work piece relative to said cutter and to be movable axially and rotatably, a cam follower and a rotatable face cam engaging said follower on said support and substantially axially aligned with said work supports and adapted to move said work support and work piece relative to said cutter, and hydraulic means for actuating said earn and reciprocating said work support and hydraulic means creating a constant load against which said work support is positioned by said cam.

EDWIN A. NICHOLS.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,724,699 Edgar Aug. 13, 1929 1,789,544 De Vlieg Jan 20, 1931 1,899,654 Ward Feb. 28, 1933 1,958,105 Koehler May 8, 1934 1,976,818 Ward Oct. 16, 1934 2,131,939 Drake et a1 Oct. 4, 1938 2,313,849 Turchan et al Mar. 16, 1943 2,395,910 Schmidt Mar. 5, 1946 2,409,993 Stupakoff Oct. 22, 1946 2,422,475 De Vlieg June 17, 1947 

